But so what?
Pain too is just product of our minds. Yet you sure know what will happen if you hit your thumb with a ten pound sledgehammer. Even though pain is not being hit on your thumb with a ten pound sledgehammer, but entirely a product of our minds.
We can play this realist vs idealist game all day, and it doesn't make one iota of a difference.
There is a correlation between our perception of colour and wavelengths of light.
Just as there is between that hammer landing on your thumb and the pain your mind produces.